The proposed research will simulate the effect of changes in insurance coverage on the level of service use, including school-based services, by children with mental health needs and on the distribution of this use among different types of mental health providers. The study will examine data from NIMH's 1992 Methodological Epidemiology of Children and Adolescents (MECA) study of 1280 community children and adolescents from 4 regions of the United States. This dataset includes detailed descriptions of the socioeconomic status of children, their use of mental health services, perceived barriers to service use, and multiple measures of mental health impairment and diagnosis. Health reform will affect the mental health insurance coverage of children by insuring the uninsured, expanding mental health coverage for most of the currently insured, moving many children currently covered by Medicaid into private health plans, and providing incentives to families to select managed-care type plans. These changes in insurance coverage are likely to alter both the level of service use and the mix of providers used by children with mental health needs. When people's insurance coverage improves, they may substitute privately-covered service providers for existing publicly-funded providers, or they may supplement their use of publicly-funded providers with newly insured services. The net effect of an expansion of insurance coverage on service use and national mental health spending will depend on the extent of such substitution between provider types among children with different mental health needs. The potential for such changes on the level and type of service use is considerable: while a generally accepted estimate of the prevalence of diagnosable psychopathology is approximately 20%, 30% of those surveyed in the MECA data expressed a need for mental health services within the last year. The proposed analysis will use an economic model of service use as a framework for simulating the effect of insurance expansion on service use.In this model, use of a particular provider type (or no provider at all), is viewed as the outcome of a two stage decision process: a decision about insurance and a provider choice. The first stage of this decision process, the choice of an insurance plan, can be studied using simple statistical models that exploit the MECA dataset's wealth of information about children's mental health impairments and diagnoses. The second stage of analysis will utilize a variety of statistical models to examine whether different types of providers are substitutes or complements. Finally, the analysis will capitalize on the four region, census tract based sampling design of the MECA study to examine the likely impact of insurance expansion on non-financial barriers to service use.